ruby-idiomslisted

# Ruby standard library and functional idioms Based on Eloquent Ruby (Russ Olsen), The Well-Grounded Rubyist (David A. Black), Ruby docs. Read the reference file (in this skill's folder) for the topic you need: - **Enumerable** — core trio, each_with_object, flat_map/filter_map/tally, group_by/chunk, lookups, including Enumerable in your own classes → `references/enumerable.md` - **Blocks, procs, lambdas** — when to use what, execute-around, yielding with args → `references/blocks-procs.md` - **Hash / Array / Set** — symbol vs string keys, dig/fetch, slice/except/merge, Set for O(1) membership, each_cons/each_slice, readable predicates → `references/hash-array-set.md` - **Ranges** — iteration, case matching, slicing, membership, `cover?` → `references/ranges.md` - **File and IO** — block form, read strategies, path building → `references/file-io.md` - **Freeze patterns** — `frozen_string_literal`, chilled strings, frozen constants → `references/freeze.md` - **Comparable / Enumerable mixins** — define `<=>`/`each` in your own classes → `references/comparable-enumerable.md` - **Structured logging** — stdlib Logger via DI, level discipline, never log secrets → `references/logging.md`